Effects of group size on performance,health and birds’ use of facilities in furnished cages for laying hens

A total of 1584 Lohmann Selected Leghorn hens were kept in 144 modified cages furnished with—perch, nest and sandbath for 5, 6, 7 or 8 hens per cage or in 162 conventional cages for 4 hens. Cage floor area was 600 cm² per hen excluding nest and sandbath. Doors to nests and sandbaths were time monitored. Production, mortality, exterior egg quality, health, integument and the birds use of facilities were registered from 20 until 80 weeks. No effects of group size or keeping system on production or mortality were detected, but the furnished cage gave more cracked and less dirty eggs than the conventional cage. Hens in the furnished cage had better plumage condition, less toe pad hyperkeratosis, shorter claws, less rear body wounds and stronger humerus, but dirtier feet than hens in the conventional cage. Hens in the larger group sizes had the dirtiest feet. In the furnished cage, on average, 86% of all eggs were laid in the nests and 0.6% in the sandbaths. The rolling out efficiency from nests was best in the larger group sizes. During night less than 0.5% of the hens stayed in the sandbath and less than 2% stayed in the nest. Average use of perches was 28% during the day and 91% at night. Hens in the small group sizes used the sandbath most. Dust‐bathing behaviour also occurred on the wire floor.     

Effects of trilostane on the pituitary-adrenocortical and renin–aldosterone axis in dogs with pituitary-dependent hypercortisolism

The medical records of 63 dogs with pituitary-dependent hypercortisolism (PDH) before and during treatment with trilostane were reviewed retrospectively. The correct trilostane dosage in dogs with PDH was based on the resolution of clinical signs and the results of an adrenocorticotropic hormone (ACTH) stimulation test. The mean (±SD) dose rate of trilostane to achieve good clinical control was 2.8 ± 1.0 mg/kg bodyweight. Trilostane treatment resulted in a significant decline in basal plasma cortisol concentrations. The median plasma ACTH concentration (39 pmol/L, range 7–132 pmol/L; n = 60) at the optimal trilostane dosage time was significantly higher (P < 0.001) than before treatment (13 pmol/L, range 2–102 pmol/L). These values did not overlap with plasma ACTH concentrations (range 212–307 pmol/L) of five PDH dogs with trilostane-induced hypocortisolism.The median cortisol/ACTH ratio in well-controlled dogs (0.23, range 0.03–2.5; n = 46) was significantly lower (P < 0.001) than before treatment (2.59, range 0.27–13.25). Trilostane treatment resulted in an insignificant decrease in plasma aldosterone concentration (PAC), but the median plasma renin activity (PRA) at the time the trilostane dosage was considered optimal (265 fmol/L/s, range 70–3280 fmol/L/s; n = 18) was significantly higher (P < 0.001) than prior to treatment (115 fmol/L/s, range 15–1330 fmol/L/s). Similarly, the median PAC/PRA ratio during trilostane treatment (0.16, range 0.003–0.92; n = 17) was significantly lower (P < 0.001) than before treatment (median 0.44, range 0.04–1.33). Trilostane affected both the hypothalamic-pituitary-adrenocortical and the renin–aldosterone axes. The results also suggested that basal plasma ACTH concentration may be used to detect trilostane overdosage.     

Perception of dogs’ stress by their owners

Questionnaires potentially have a broad applicability in measuring stress levels in dogs, as owners know their dogs’ behavior and personality better than anyone else. The aim of this research was to evaluate how owners perceive stress in their dogs through understanding of displayed behaviors.The survey was carried out using 1,190 questionnaires completed by dog owners. More than half of respondents were able to correctly identify stress as a short- or long-term alteration of the psychophysical equilibrium that can develop into illness. This ability was higher with higher educational levels. The behavioral indicators of stress most frequently identified by owners were trembling and whining, followed by aggressiveness, excessive barking, and panting. More subtle behaviors such as looking elsewhere, turning head, yawning, and nose licking were more rarely reported, suggesting that few owners are able to correctly interpret and intervene in early stages of stress. The vast majority of respondents indicated that dogs were stressed seldom or only in specific situations. Men generally considered their dogs as experiencing low stress more often than did women, whereas women considered their dogs as being moderately stressed more often than did men.An owner’s ability to recognize behavioral signs of stress is important, as it enables the owner to help the animal to avoid welfare problems, such as stressful situations, and favors a rapid recovery of psychophysical homeostasis by interrupting the progression to overstress and distress. The results show that some owners can help in protecting the welfare of their dogs, but that many owners would benefit from educational efforts to improve their ability to interpret their dogs’ behavior.     

Survey of giardiosis in household and shelter dogs from metropolitan areas of Curitiba, Paraná state, Southern Brazil

Giardia duodenalis is a protozoan parasite that causes a broad range of clinical symptoms varying from none--in asymptomatic carriers--to mild recurring diarrhea consisting of soft, light-colored stools to acute severe diarrhea. In different parts of the world this parasite has raised increased interest due to its possible zoonotic transmission. Among domestic animals, dogs can play an important role in environmental contamination. As there is little information on the frequency of giardiosis in dogs from the Metropolitan Area of Curitiba-State of Paraná, Southern Brazil, the aim of the present work was to evaluate the prevalence of G. duodenalis in two dog populations (household and shelter). To attain the proposed aim, we collected fecal samples from 200 dogs and utilized three diagnostic techniques: Faust's technique (Faust et al. 1939), Benbrook's technique (1963) and polymerase chain reaction (PCR). Faust's technique presented the best results, as it was able to detect a larger number of Giardia cases. Taking Faust's technique as the standard, Benbrook's technique presented 66% sensitivity and PCR demonstrated 69% sensitivity. The shelter dog population showed a 24% occurrence of G. duodenalis while the household population showed a 9% occurrence. Other epidemiological aspects like age, sex, environmental conditions and methodological aspects are discussed in the present article.     

Relationship between latency of brainstem auditory‐evoked potentials and head size in dogs

Summary

Cranium and brainstem dimensions were measured in 32 postmortem dog heads. Positive correlations were found between cranium length (CL) and brainstem length (BL) (r=0.87), between cranium width (CW) and brainstem width (BW) (r=0.83), and between cranium distance (CD = CL CW/2) and brainstem distance (BD = BL+BW/2) (r=0.91). Positive correlation coefficients were also found between CL and CW (r=0.90), and between BL and BW (r=0.85). It was concluded that head size accurately reflected brainstem size. A least squares estimation of the brainstem distance (BD) from CL and CW values was BD = 10.9 + 0.16 (CL CW/2) (BD, CL and CW in mm).

Brainstem auditory evoked potentials (BAEPs) and cranium dimensions were measured in 43 dogs (86 ears) with different head size, body size, sex and age. Wave form, absolute and interpeak latencies and correlation coefficients, relating latencies to cranium dimensions and body weight, were analysed CL, CW, and CD were positively correlated with body weight (r=0.93, 0.70 and 0.93, respectively), and CL, CW, and CD were correlated with age (r=0.33, 0.52 and 0.40, respectively). BAEPs consisted of five distinct positive peaks (I to V). Secondary positive peaks following peaks I and II were seen in 60% (I') and 90% (II') of the recordings. Late waves were recorded in 90% (VI), 50% (VII), and 25% (VIII) of the recordings. Latencies increased with decreasing stimulus intensity level (from 90 dB to 10 dB hearing level, HL),especially for peaks I, II, V, and the I‐V interpeak interval Absolute and interpeak latencies were positively correlated with cranium distance and body weight. Correlation coefficients increased as wave latencies increased At 90 dB HL, the highest correlation coefficients, relating cranium distance to peak V and the I‐V interpeak latency, were 0.55 and 0.53 (P < 0.00001), respectively. Regression analysis showed that each 1 cm increase in cranium distance was accompanied by an increase of 0.006 ms in the latency of wave I, 0.03 ms for wave III, 0.05 ms for wave V, and 0.05 ms for the I‐V interpeak interval Regression analysis showed that an increase of 1 kg in body weight was accompanied by an increase of 0.001 ms in the latency of wave I, 0.005 ms for wave III, 0.011 ms for wave V, and 0.01 ms for the I‐V interpeak interval. It is concluded that head size, which accurately reflects brain size, is a relevant source (25%) of intersubject variance of BAEP latencies in the dog.     

Does the computed tomographic appearance of the lung differ between young and old dogs?

In computed tomographic (CT) images of humans, decreased lung attenuation, bronchial dilation, and/or thickening, air trapping, cysts, and thickened interlobular septa have been associated with increasing age. To determine if there are differences in the CT appearance of the lungs of young and old dogs that could affect interpretation of diagnostic studies, pulmonary CT images of dogs with conditions unrelated to the thorax were reviewed retrospectively in a case–control study. Computed tomography studies of 42 young dogs (range 0.3–4.8 years) and 47 old dogs (range 9–15.1 years) were jumbled and reviewed by an observer blinded to dog age. Computed tomography was performed under sedation in 62 (70%) dogs and under general anesthesia in 27 (30%). Heterotopic bone was more prevalent (62% vs. 14%) in old dogs. Lung collapse was significantly associated with old age, greater body weight, and anesthesia. There were no significant differences in median lung attenuation or occurrence of ground glass pattern, cysts, bronchial thickening, bronchial dilation, or degree of tracheal calcification. No examples of reticular pattern, emphysema, pleural thickening, or septal thickening were observed in any dog. Despite previous studies describing age‐related changes in the radiographic appearance of the lungs of old dogs, it appears that there are minimal observable differences in CT images. Old dogs are more likely to have visible foci of heterotopic bone and may be more prone to lung lobe collapse than young dogs, but neither of these differences should contribute to misdiagnosis of pulmonary disease.     

Effects of interferon-γ knockdown on vaccine-induced immunity against Marek’s disease in chickens

Interferon (IFN)-γ has been shown to be associated with immunity to Marek’s disease virus (MDV). The overall objective of this study was to investigate the causal relationship between IFN-γ and vaccine-conferred immunity against MDV in chickens. To this end, 3 small interfering RNAs (siRNAs) targeting chicken IFN-γ, which had previously been shown to reduce IFN-γ expression in vitro, and a control siRNA were selected to generate recombinant avian adeno-associated virus (rAAAV) expressing short-hairpin small interfering RNAs (shRNAs). An MDV challenge trial was then conducted: chickens were vaccinated with herpesvirus of turkey (HVT), administered the rAAAV expressing shRNA, and then challenged with MDV. Tumors were observed in 4 out of 10 birds that were vaccinated with HVT and challenged but did not receive any rAAAV, 5 out of 9 birds that were administered the rAAAV containing IFN-γ shRNA, and 2 out of 10 birds that were administered a control enhanced green fluorescent protein siRNA. There was no significant difference in MDV genome load in the feather follicle epithelium of the birds that were cotreated with the vaccine and the rAAAV compared with the vaccinated MDV-infected birds. These results suggest that AAAV-based vectors can be used for the delivery of shRNA into chicken cells. However, administration of the rAAAV expressing shRNA targeting chicken IFN-γ did not seem to fully abrogate vaccine-induced protection.     

Molecular detection and phylogenetic analysis of ‘Candidatus Bartonella merieuxii’ in dogs and its effect on hematologic parameters

Emerging Bartonella spp. infection can result in clinical symptoms such as endocarditis in humans and animals. This study analyzed the genetic phylogeny of the Bartonella spp. circulating in Iranian dogs. Also, this is first study on the relationship of Bartonella spp. and haematological factors from dogs in Fars. Ninety-eight blood samples were collected from the dogs of Fars province, Iran. Two different PCRs targeting rpoB gene and ITS sequence of Bartonella spp., followed by sequencing were performed. In addition, CBC and the differential count of WBC were determined. The “prevalence” of Bartonella spp. was 12.2 % (95 % CI: 5.72–18.68 %) in this population and the sequences matched with a newly proposed species; ‘Candidatus Bartonella merieuxii’. A significant increase in WBC due to neutrophilia and decreased RBC, Hct, and Hb concentrations were detected in Bartonella spp. infected dogs. The close contact between humans and dogs, and the zoonosis potential of Candidatus Bartonella merieuxii, emphasize on the need for more studies on ‘Candidatus Bartonella merieuxii’.     

Effects of force‐feeding and dietary cereals on gastrointestinal size,intestinal absorptive ability and endogenous nitrogen in ducks

1. Gastrointestinal size, intestinal absorption of glucose and L‐methionine, and intestinal endogenous nitrogen in Pekin ducks were measured after the birds were subjected to force‐feeding with excessive amounts of a diet based on maize or barley for 12 d.

2. Force‐feeding significantly increased the weight and area of the crop, the weight of the proventriculus, the length and area of the jejunum and ileum, but decreased the weight of the gizzard and the thickness of its caudodorsal thick muscle. Feeding a barley‐based diet also decreased the thickness of caudodorsal thick muscle of gizzard.

3. Force‐feeding enhanced the absorption rates (μmol/cm²) of glucose and L‐methionine in both jejunum and ileum. Ducks fed on a maize‐based diet showed a slightly higher absorption rate of glucose compared to those fed on a barley‐based diet.

4. Force‐feeding caused a significant increase of endogenous non‐protein nitrogen (μg/cm²/h) in both jejunum and ileum and a slight increase of endogenous protein nitrogen in the jejunum.     

Effects of structure and xylanase treatment of brewers’ spent grain on performance and nutrient availability in broiler chickens

1.?A factorial (2 × 3) feeding trial was set up to investigate the effects of coarse or finely ground brewers’ spent grain (BSG) and xylanase treatment, either with no xylanase, top-dressed with xylanase or pre-treated with xylanase.

2.?The experimental diets shared the same basal formulation and were fed to male broiler chickens (Ross 308) housed in individual cages from 12 to 29 d of age.

3.?Xylanase pre-treatment reduced the dietary concentration of arabinoxylan by 15–30%. Pellet durability increased when BSG was ground.

4.?Feed utilisation was significantly higher (6%) when the birds were given coarse BSG rather than ground BSG, whereas there was no significant effect of enzyme treatment. Apparent metabolisable energy was unaffected by the dietary treatments.

5.?The overall starch digestibility was high (99%), with no dietary differences, whereas ileal protein digestibility was low (57%). Xylanase top-dressing tended to improve ileal protein digestibility but, in general, xylanase treatment had no major effect on overall performance in male broilers given diets with BSG.     

Effects of avgard™ treatment on the microbiological flora of poultry carcases

1. The efficiency of the AvGard? (or Assur‐Rince? in the USA) trisodium phosphate poultry carcase decontamination process was evaluated during both manual and industrial trials against total aerobic mesophilic count (TAMC), thermotolerant coliforms, Pseudomonas, Enterobacteriaceae, Campylobacter, Listeria monocytogenes and Salmonella.

2. The TSP treatment proved to have significant effects on the bacterial decontamination of poultry neck skin, lowering the contamination by a factor of about 10 for TAMC and of 100 for Coliform and Pseudomonas.

3. Numeration of Salmonella with an innovative miniaturised most probable number method has proved that the effect upon these micro‐organisms was also close to 2 log₁₀ reduction.

4. The effect of TSP treatment on the ecological balance of psychrotrophic bacterial flora was also investigated to study the origin of the shelf‐life flora of treated carcases (Pseudomonas being reduced to the limit of detection) and to ascertain whether L. monocytogenes might gain a competitive advantage. In fact AvGard? reduced the number of L. monocytogenes on poultry carcases.

5. As a consequence of the virtual elimination of the Pseudomonas usually present, Brochothrix thermosphacta became the main species responsible for putrefaction.

6. Because the growth rate of Brochothrix thermosphacta was greater than that of L. monocytogenes at refrigeration temperature, it was considered that putrefaction would occur before the emergence of large numbers of L. monocytogenes.     

Effects of substituting sow and weaner meal with brewers’ spent grains on the performance of growing pigs in Rwanda

Nutrient composition of brewers’ spent grains (BSG) from two industries and sow and weaner meal (SWM) were different (p < 0.05). In completely randomised design (CRD), thirty (30) Landrace x Pietrain crosses 35 to 40 ± 5 kg were randomly allocated to 10 pens each with 3 pigs based on the initial weight. Five diets were assigned to pig, where BSG replaced SWM at 0% (T1), 25% (T2), 50% (T3), 75% (T4) and 100% (T5) on DM basis. Daily feed intake and weekly live weight, feed conversion ratio (FCR) and the net profit were recorded for 42 days. Feed intake increased from T1-T3 and then decreased (p < 0.05). The average daily gains (ADG) were different (p < 0.05), but T1 to T3 were similar (p > 0.05). FCR was similar (p > 0.05) from T1 to T3 but different for T4 and T5 (p < 0.05). Feed cost decreased with the increase in BSG levels. The net return was highest in T3 (50% BSG) than in T1 and T2 but lower in T5. It was concluded that BSG can replace 50% SWM in grower pigs’ diets without adverse effect on daily gain with good economic returns.